SER or NM ?

[TwistLock]

I typically see SER with bare ground. In photo below the ground is insulated. Since this place was built in the ’70’s I’m just curious if there was NM available in #2 AL and or a distinction between SER back then - and if it even matters for the 83% rule, formerly 310.15(b), for a feeder from a meter-main.
I.e. if this were #2 AL NM (not listed as SER) would I still be allowed to protect it with a 100a breaker at meter-main or is it just a stepchild at 60C ? *(can't see any markings on jacket with what is visible at either end).

 

[Eddie702]

looks like nm to me. installed in the 70s that was aluminum time. What size is the ground? Looks undersized for SER which usually has a larger ground than NM

 

[infinity]

It looks like a larger version of the same cable type which is right next to it on the right side in the photo. That jackets says NM 600V.

 

[TwistLock]

"...What size is the ground? Looks undersized for SER which usually has a larger ground than NM "

It’s a job someone walked on & I’m thinking of taking it over so I took some quick photos and did measure the neutral while there (pic below), but didn’t bother with the ground. You’re right though, it’s hard to tell if ground is #8 or #6. Maybe they used a really thin jacket, compared to the thick jacket on CCC’s, back then since it was the ground(?)


" It looks like a larger version of the same cable type which is right next to it on the right side in the photo. That jackets says NM 600V. "

Yes, that caught my eye too, they're buddies.

 

[Birken Vogt]

SER ground is always equal or 2 AWG sizes smaller than the main conductors since it is intended to be used as neutral return in a service. So what you have there has to be NM cable. Also SER has fiberglass tape and the picture appears to be paper in the cable which would make it NM. SE cables have no paper since they are intended to be outdoors.